feat: keep stream error toggle open by default

[uinstinct]

Description

Keep the error dialog toggle open by default.

resolves CON-4376
related to #8215

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Checklist

• [] I've read the contributing guide
• [] The relevant docs, if any, have been updated or created
• [] The relevant tests, if any, have been updated or created

Screen recording or screenshot

feat.mp4

Tests

[ What tests were added or updated to ensure the changes work as expected? ]

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Summary by cubic

Open the stream error details by default so error output is visible immediately and debugging is faster. Addresses CON-4376.

• New Features
  • Added a defaultOpen prop to ToggleDiv to control initial open state.
  • Enabled defaultOpen in StreamError for the “View error output” section.

^{Written for commit 3118030. Summary will update automatically on new commits.}

[cubic-dev-ai]

No issues found across 2 files